Rectal Bleeding - Information for Referring Clinicians
Rectal bleeding is a common symptom. Patients frequently present to their general practitioner with rectal bleeding and need to be assessed and considered for further investigations. Assessment includes clarification of the amount and duration of bleeding, presence of associated symptoms, such as constipation and diarrhoea and the age and general well being of the patient.
In addition to overt rectal bleeding, patients are increasingly being diagnosed with presumed gastrointestinal blood loss as a result of routine laboratory investigations including routine blood test that show evidence of anaemia and stool sample analysis (faecal occult blood tests).
Faecal occult blood tests (FOBT) help detect slow gastrointestinal bleeding, in the absence of overt symptoms. Causes can include pre-cancerous colonic polyps. Removal of these polyps can prevent the development of colorectal cancer. Other causes can include bleeding from the upper gastrointestinal tract, from ulcers and other conditions such as oesophagitis.
FOBT are of value in asymptomatic patients. Unfortunately the test can be falsely negative and a negative test does not exclude a serious colonic lesion, such as colonic polyp or cancer. Furthermore FOBT is of little value in a patient with a history of rectal bleeding, anaemia or symptoms that would justify investigation.
Causes of rectal bleeding include benign conditions such as skin tags, haemorrhoids and anal fissures. More serious causes can include colitis and colonic polyps, diagnosed at colonoscopy. In addition positive FOBT can be due to upper gastrointestinal blood loss due to gastric ulcers diagnosed at gastroscopy.
If a patient has a history of rectal bleeding or positive FOBT they should be considered for referral to a specialist clinic and assessed for further investigations. Investigations, such as colonoscopy can be arranged following assessment of symptoms, family history of malignancy and physical examination. Sigmoidoscopy and colonoscopy enable a direct, detailed assessment of the rectum and colon and provide an opportunity to diagnose and treat conditions. Polyps can be removed and colorectal cancer can be prevented.
Patients with rectal bleeding should be initially assessed by an experienced colorectal surgeon in a dedicated clinic with both medical and surgical expertise.